Diff: mbed-os/drivers/BusOut.h

Revision:

0:6bf0743ece18

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/drivers/BusOut.h	Sat Mar 28 15:28:19 2020 +0000
@@ -0,0 +1,127 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_BUSOUT_H
+#define MBED_BUSOUT_H
+
+#include "drivers/DigitalOut.h"
+#include "platform/PlatformMutex.h"
+#include "platform/NonCopyable.h"
+
+namespace mbed {
+/** \addtogroup drivers */
+
+/** A digital output bus, used for setting the state of a collection of pins
+ * @ingroup drivers
+ */
+class BusOut : private NonCopyable<BusOut> {
+
+public:
+
+    /** Create an BusOut, connected to the specified pins
+     *
+     *  @param p0 DigitalOut pin to connect to bus bit
+     *  @param p1 DigitalOut pin to connect to bus bit
+     *  @param p2 DigitalOut pin to connect to bus bit
+     *  @param p3 DigitalOut pin to connect to bus bit
+     *  @param p4 DigitalOut pin to connect to bus bit
+     *  @param p5 DigitalOut pin to connect to bus bit
+     *  @param p6 DigitalOut pin to connect to bus bit
+     *  @param p7 DigitalOut pin to connect to bus bit
+     *  @param p8 DigitalOut pin to connect to bus bit
+     *  @param p9 DigitalOut pin to connect to bus bit
+     *  @param p10 DigitalOut pin to connect to bus bit
+     *  @param p11 DigitalOut pin to connect to bus bit
+     *  @param p12 DigitalOut pin to connect to bus bit
+     *  @param p13 DigitalOut pin to connect to bus bit
+     *  @param p14 DigitalOut pin to connect to bus bit
+     *  @param p15 DigitalOut pin to connect to bus bit
+     *
+     *  @note Synchronization level: Thread safe
+     *
+     *  @note
+     *  It is only required to specify as many pin variables as is required
+     *  for the bus; the rest will default to NC (not connected)
+     */
+    BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
+           PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
+           PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
+           PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
+
+    /** Create an BusOut, connected to the specified pins
+     *
+     *  @param pins An array of pins to connect to bus the bit
+     */
+    BusOut(PinName pins[16]);
+
+    virtual ~BusOut();
+
+    /** Write the value to the output bus
+     *
+     *  @param value An integer specifying a bit to write for every corresponding DigitalOut pin
+     */
+    void write(int value);
+
+    /** Read the value currently output on the bus
+     *
+     *  @returns
+     *    An integer with each bit corresponding to associated DigitalOut pin setting
+     */
+    int read();
+
+    /** Binary mask of bus pins connected to actual pins (not NC pins)
+     *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
+     *
+     *  @returns
+     *    Binary mask of connected pins
+     */
+    int mask() {
+        // No lock needed since _nc_mask is not modified outside the constructor
+        return _nc_mask;
+    }
+
+    /** A shorthand for write()
+     * \sa BusOut::write()
+     */
+    BusOut& operator= (int v);
+    BusOut& operator= (BusOut& rhs);
+
+    /** Access to particular bit in random-iterator fashion
+     * @param index  Bit Position
+     */
+    DigitalOut& operator[] (int index);
+
+    /** A shorthand for read()
+     * \sa BusOut::read()
+     */
+    operator int();
+
+protected:
+    virtual void lock();
+    virtual void unlock();
+    DigitalOut* _pin[16];
+
+    /* Mask of bus's NC pins
+     * If bit[n] is set to 1 - pin is connected
+     * if bit[n] is cleared - pin is not connected (NC)
+     */
+    int _nc_mask;
+
+    PlatformMutex _mutex;
+};
+
+} // namespace mbed
+
+#endif